The invention relates to the field of converters such as inverters, for example those used in uninterruptible power supplies, in particular high-power uninterruptible power supplies, i.e. with a power that is generally comprised between about 100 and 500 kVA.
The invention more particularly relates to a converter device enabling an AC voltage and current to be supplied by filtering pulses obtained on a modulated signal output from three substantially DC voltages available on a reference voltage line and on two voltage inputs of opposite signs, said device comprising two switching units connected between said reference voltage line and respectively one and the other of said inputs, each switching unit comprising first switching means connected between the input to which said switching unit is connected and a switching output of said switching unit to supply pulses having the same sign as that of the voltage available on said input by main turn-ons and turn-offs of said first switching means, said device comprising, for each switching unit, second switching means associated with said switching unit and connected between said switching unit and said modulated signal output, and first control means acting on said second switching means to establish turn-on of said second switching means when the sign of said AC voltage is the same as that of the voltage on the input to which said switching unit is connected.
The invention also relates to an uninterruptible power supply comprising a power supply input on which an AC input voltage is applied, a rectifier connected to said input, two substantially DC voltage lines of opposite signs connected on output of said rectifier, an inverter connected to said voltage lines of substantially DC voltage and comprising an output designed to supply a backed-up voltage.